For example, in a manufacturing process of a semiconductor device, there is single wafer type liquid processing of rotatably holding a semiconductor wafer (hereinafter, referred to as a “wafer”) which is a substrate to be processed around a vertical shaft and supplying various chemical liquids (processing liquids) onto a target surface while rotating the wafer. A wafer completed with a liquid processing is subjected to a rinse cleaning for removing the chemical liquids by supplying a rinse liquid such as deionized water (DIW) to the surface of the wafer to be processed or a drying processing for removing the rinse liquid from the wafer while continuously rotating the wafer.
A liquid processing apparatus performing the single wafer type liquid processing supplies a corrosive chemical liquid such as hydrofluoric acid to the bottom surface of the rotating wafer which is an opposite surface to a circuit forming surface of the wafer to remove an undesired film formed on the bottom surface. In this type of liquid processing apparatus, there is a phenomenon in which the chemical liquid dispersed to the entire bottom goes around and flows onto the top surface of the wafer by the action of surface tension of the liquid. When the chemical liquid goes around and reaches to the circuit forming surface of the wafer, a semiconductor device formed on the circuit forming surface may be damaged.
Accordingly, Japanese Patent Application Laid-Open No. 2010-28059 discloses a liquid processing apparatus that can prevent the chemical liquid from going around and flowing onto the circuit forming surface by installing a supporting unit that supports the wafer in a rotating cup guiding the chemical liquid dispersed from the wafer to a discharge mechanism, and by placing the rotating cup at a location close to the wafer. See, for example, claim 1, paragraphs [0020]-[0022] along with FIGS. 1 to 4 of Japanese Patent Application Laid-Open No. 2010-28059. The inventor of the present disclosure has carried out a study in order to further reduce the amount of the liquid that goes around and flows onto the top surface.